The predictive values of urinalysis in intravenous urogram. Is intravenous urography really necessary in mild hydronephrotic patient?

Background and Aims. Many patients who presented to Universiti Kebangsaan Malaysia Medical Centre (UKMMC) with signs and symptoms of urolithiasis had mild hydronephrosis with non visualization of calculus on ultrasound examination. These patients underwent an intravenous urogram (IVU) in order to determine the presence of urolithiasis and most of them had normal IVU. The main aim of this study was to determine the predictive value of urinalysis in this group of patients in determining the need for IVU examinations. Materials and Methods. Retrospectively the ultrasound, urinalysis and intravenous urography reports of 53 patients were reviewed and evaluated. Results. The positive predictive and negative predictive value of urinalysis was found to be 68% and 96.4%, respectively. Conclusions. The results indicate that the urinalysis was an excellent negative predictor for IVU. In view of high radiation dose, risk of contrast reaction and contrast induced nephropathy of IVU, we suggest that it should not be performed in patient with non visualization of calculus mild hydronephrosis when the urinalysis is negative for blood.